Since 1922 Japan had been unhappy with the existing naval status quo. Japan had wanted parity with the Royal Navy and especially the United States Navy but under the terms of the Washington Treaty had been allocated 70% the strength of the other two powers. The Japanese felt cheated by the two western powers. Japan saw herself as the dominant power in Asia and felt that the two democracies had conspired to hamstring her future. In her view another stipulation of the Treaty in addition to the portion of the tonnage of the other two indicating this was the dissolution of Japanese-British Treaty. It didn’t matter that Japan was on the verge of bankruptcy in her increasing naval construction race against the USN. The fact was her perceptions varied from reality and she was deprived her place in the sun. From the start of the Washington Treaty Japanese designers had tried to make every warship design qualitatively superior to equivalent RN and USN designs. Japanese designers came up with some ingenious methods to save weight, such as the undulating sheer line and the use of armor belt directly on the framing rather than on top of plate sheathing. Not all of their theories worked and they were further handicapped by design theorems that always seemed to produce designs heavier in reality than as designed. At first the displacement over-runs were through accident and later as more features were needed, the designs were intentionally over treaty displacement. Whether through accident or intent, the Japanese Navy would lie about the actual displacement and state that these designs were under the treaty limitations.
The London Treaty of 1930 kept the ratios of the world’s navies and unlike the Washington Treaty capped cruiser tonnage. The Japanese admirals were already anticipating getting out of the treaty the next time it came up for renewal and were undertaking experimental super-battleship designs. In the mean time the Imperial Japanese Navy could take steps to prepare for a rapid expansion of the Japanese Navy beyond treaty limitations. In 1934 the admirals came up with the idea of the "Shadow Fleet". This meant design one type of ship readily able to be converted into another type. The first design to employ this concept was the Chitose class seaplane tenders. This design could be converted into fast oilers or aircraft carriers. Other "Shadow Fleet" vessels followed. The greatest of the "Shadow Fleet" program were two 27,500-ton passenger liners to be named Izumo Maru and Kashiwara Maru. Taken over by the navy for completion as carriers, they became the fleet carriers Hiyo and Junyo.
Winston Churchill is rightly seen as one of the fathers of the escort carrier and although the Royal Navy had a few escort carriers converted from merchant ships in Great Britain, it was the USA that mass-produced the CVE for both the RN and USN. However, Japan had also undertaken the conversion of merchant ships into aircraft carriers. Not designed from the start for conversion, as in the "Shadow Fleet" program, this line of carriers had the same source for hulls as in the RN and USN programs, converted merchant ships. The first merchants taken over by the Japanese Navy were three 17,100-ton passenger liners Kasuga Maru, Yawata Maru and Nitta Maru, which became the carriers Taiyo, Unyo and Chuyo. One way in which "Shadow Fleet" ships can be distinguished from pure merchant conversions is in their top speed. The passenger liner "Shadow Fleet" passenger liner conversions for Hiyo and Junyo had a top speed of 25.5- knots, while the passenger liner conversions for the Taiyo class carriers only had a top speed of 21-knots. Of course the Taiyo class were much larger than RN and USN CVEs and had an aircraft complement of 27. The Taiyo was the first to commission on September 1941 with the other two following in 1942.
After the successful conversion of the Taiyo class carriers from passenger liners the IJN started grabbing up other merchant ships. Since Japan needed every cargo ship and oiler that it could get its hands on, many of the merchant conversions into carriers were originally passenger liners. Two such liners were the Argentina Maru, laid down on February 22, 1938 by Mitsubishi as a 12,755-ton passenger liner and Brazil Maru. On December 9, 1938 the Argentina Maru was launched, still on course for a peaceful life as a liner. Capable of 24 knots, the incomplete Argentina Maru soon fell under the gaze of the Imperial Japanese Navy. In late 1941 the navy took over the ship, not for conversion as an aircraft carrier, but as a troop transport. Plans for any further conversion of Brazil Maru promptly ended in August 1942 when the ship was sunk. By 1942 it was decided that the sister ship’s future would be as an aircraft carrier. The liner Argentina Maru then metamorphosed into the aircraft carrier Kaiyo. The carrier conversion started in late 1942 but the ship still took a year to convert and she was commissioned November 23, 1943. Destroyer turbines replaced the liners diesel engines. A hangar was built on top of the hull with a light wooden flight deck, served by two elevators, on top. Sponsons were provided on the hull sides for four twin 5-inch DP guns and six triple 25mm light AA mounts with two more triple 25mm mounts on a platform over the stern.
Although the Kaiyo had no catapult and no island, the ship had a Type 21 radar mounted on the starboard flight deck edge. The carrier had an overall length of 546-feet (523-feet wl) and a trial displacement of 16, 483-tons. In 1944 her AA complement was increased with twenty more 25mm guns, as well as eight barreled rocket launchers, of the same type as fitted of Ise and Hyuga. Like the much earlier RN UP launchers of 1941, the Japanese rockets would trail wires, which were hoped to entangle attacking aircraft. As with the British UP rockets, there is no record of the Japanese version knocking down an allied aircraft. Although they may not have been effective in their intended role, there was a beneficial side effect. It is said that at the Battle of Cape Engano, Halsey,s carrier pilots steered clear of the Ise and Hyuga because of the fearsome appearance of their rocket volleys. Whether true or not, the Ise and Hyuga survived the battle while all of Ozawa’s carriers were lost. Until mid 1944 the Kaiyo actually served as an aircraft transport, ferrying aircraft from the home islands to perimeter air bases. For the rest of the war she served as a training carrier for minimal training of the green aircrew. On July 24, 1945 the FAA in the form of aircraft from HMS Formidable, Indefatigable and Victorious found Kaiyo in Beppu Bay off the island of Kyushu. The Kaiyo was damaged in the attack and run ashore to prevent sinking. The war had only weeks to go so the carrier was never repaired and was broken up after the war in Beppu Bay at the spot in which she grounded. (Kaiyo history from: Aircraft Carriers of the World , 1914 to the Present, Naval Institute Press, Annapolis, Maryland 1984, by Roger Chesneau)
Port Side & Flight Deck – Sprue A
You can certainly see the merchant origins of Kaiyo from the port side hull piece. Instead of the knife edge cutwater of a merchant, the Kaiyo has the more bluff and wide cutwater and bow of a merchant ship. Another almost sure giveaway to her merchant origins is at the stern. Here long rectangular openings of an open gallery normally associated with a passenger ship for the use of passengers in their promenades. These are not openings into the hangar, as they are aft of the hangar and one deck lower. It is somewhat surprising why these openings were still there instead of being plated over in the conversion process. For whatever reason they remained, it is to the benefit of the modeler, as those open galleries provide a very unusual naval architectural feature. There are plenty of other features and decorations on the hull sides between the bow and stern. The anchor housing is inset into the hull as opposed to just hanging from the side. On the forecastle are positions for the first two triple 25mm mounts. To place them as far outboard as possible in order to give a good arc of fire, they partially overhung the hull sides. A triangular sponson, like a half an ice cream cone provided to outboard support for these positions. Also built outboard are five large position or features. From looking at the box art the first small rectangular position had open windows with some type of fittings within. The next four fittings on the sides of the hull appear to be strengtheners to provide support to the amidship galleries, placed outboard just below flight deck level.
Where the forecastle ends and the hangar begins there is a prominent knuckle, clearly indicting where the hangar was slapped on top of the hull. In the photographs you’ll see a series of long horizontal openings but these are slots for the various gallery parts to provide a good fit for those galleries. The flight deck is the second major item on A sprue. The Kaiyo had a wooden flight deck and there is no wood plank detail on the Fujimi kit, which means that either Fujimi decided not to provide the plank detail or else that the deck was sheathed in metal, which was not mentioned in the reference, which I consulted. Raised detail on the deck appear to be eight series of arrestor wires and two crash barriers/windscreen forward. Both elevators are cleanly delineated with incised lines. Another oddity of the flight deck is a raised line slightly inboard of the edge of the flight deck. It almost looks like a low scupper and it runs around the entire circumference of the deck, including the forward and aft round downs. It would seem that this could have posed a problem for take offs and landings but I had no close up deck photographs of Kaiyo to see what feature this may have been. The outlines for searchlight elevators are present in front of the front elevator and to the left side of the aft elevator. This type of position was common in Japanese carriers in that the fittings were retracted below the flight deck for operations and were raised above the flight deck when there were no flight operations. From amidships to the stern there are a series of light galleries ringing the flight deck sides, which appear to have solid splinter shielding but that shielding appears to be too low. The bottom of the flight deck as under-deck support girder detail under the flight deck overhangs of the forecastle and quarterdeck.
Eight larger galleries comprise the rest of A sprue. The larger five have star shape support ribs on the bottom of the their piece. The two largest are for the five-inch gun positions on each side. Five of the remaining six parts are for 25mm mount platforms. All of the triple 25mm mounts are open except the closed mount on the starboard side just aft of the funnel, which was closed to keep out exhaust fumes. The last platform provides the base for the mast. These galleries have a peculiar assortment of side splinter screens. One 5-inch gallery has a full height splinter shield, while the other has no splinter shielding at all, while the 25mm platforms have half height splinter shielding. I have noticed with other kits at Japanese warships that any splinter shielding for 25mm appears more as scuppers, apparently so their field of fire is not impeded.
Starboard Side, Forecastle, Quarterdeck & Bridge – Sprue B
The second or upper level of the hangar front face is a separate part. It has a platform that overhangs the forecastle almost to the breakwater and most interestingly has a large rectangular recess at centerline. This is because the location of the recess is the location of the bridge, which is supplied as a photo-etch part with open square windows. Fujimi is to be applauded for this approach as it provides far more detail than just have the bridge molded onto the platform. Now the modeler can actually glaze the bridge windows with Micro-Klear rather than just paint them black. Among the other larger parts on this sprue are the aft quarter sponsons, aft 25mm platform, more side galleries, two-piece stack, small radio antennae galleries, and aft hangar bulkhead. Additionally there are quite a few smaller fittings and parts on this sprue. These include: radio antennae; mast; flight deck support pillars; and platform support pillars.
Hull Bottom, Armament & Fittings – Sprues C
Sprue C has one parts and that is the hull bottom and two athwartship supports. Although you could certainly build the model without that piece, it certainly will add rigidity to the hull. Additionally, as has always been present since the introduction of the waterline 1:700 scale series, metal weights are provide, which adds additional heft to the model. The kit has two identical D sprues, which provide all of the armament, fittings and equipment. You’ll have spares from these sprues as all are not used. There are two different 5-inch mount designs. For the port side they are the tradition mounts with open backed gun shields. However, on the starboard side the 5-inch mounts are fully enclosed in order to prevent stack exhaust from interfering with their operations. Likewise, you’ll find a fully shielded triple AA position found only at one location, just aft of the funnel. The best-detailed guns are the open 5-inch gun mounts, followed by the closed 5-inch and triple 25mm mounts. The open 25mm mounts are one piece affairs that are adequate but really lack detail. Other fittings that are used are the anchors, searchlights, ship’s boats, and davits. Each sprue also provides six single 25mm guns but these are not used with Kaiyo, as she had entirely triple mounts.
Aircraft, Photo-Etch and Decals
As mentioned sixteen aircraft are provided in clear plastic. The mix of types includes four Zekes/Hamps, four Vals, four Kates and four Nakajima B6N2 or B7A Grace. Although, there are no extra parts for the aircraft, there is elevator lines , stabilizer lines, panel lines and canopy frame detail. Landing gear is in the old peg form, so many modelers may wish to add extra 3rd-party detail on the aircraft. The stainless steel photo-etch fret has seven ship specific parts. First is the navigation bridge with it open square windows. It is easy to fold to the correct shape, as there are only a couple of joints attaching the panels at the fold points. The next two largest pieces are two triangular platforms and lattice structures that jut outboard on each side of the stern. The platforms are fully perforated, although the actual perforations may be over-scale. There is an intricate lattice work brace that supports the single funnel of the ship. The stack also gets a grating. Lastly are found the two covers for the retractable flight deck positions. The modeler will need to supply their own railing, inclined ladders and vertical ladders. The decal sheet provides 64 national aircraft markings in various sizes. Since each aircraft requires six decals, there are only enough decals for ten of the sixteen aircraft, unless you leave the under-wing decals off, which is fine since the under-wing area of each 1:700 scale aircraft is not normally seen.
The instructions for the Fujimi Kaiyo come in the form of one large back-printed sheet. About have of the front page has a history of the ship in Japanese and general instructions in English, German, Spanish, French and Japanese. The lower half of the front has a painting guide, plan, profile and parts/sprue laydown. The back of the sheet uses clear drawings and parts’ numbers to depict assembly of the carrier in 20 steps. Actually the first 17 steps are subassemblies, showing attachment of the armament, equipment and fittings to the various platforms, decks and galleries. Step 18 covers attachment of the starboard galleries and stack to the hull with an inset about the photo-etch stack brace. Step 19 covers the forecastle and platform, navigation bridge, port galleries and quarterdeck. Step 20 covers attachment of the flight deck and supports, aft 25mm platform and aircraft decal placement. The instructions are straight forward and since there are not that many parts needed for assembly, should be more than adequate for the purpose.
Fujimi provides one of the lesser-known Japanese aircraft carriers of World War Two in the form of the Kaiyo in 1:700 scale. The kit includes a ship specific photo-etch fret that allows glazed bridge windows. This converted passenger liner may not have the name recognition of Akagi or Kaga but it did have one thing they did not, it survived the war. As an added bonus, it will appeal to British modelers as the FAA roughed her up in July 1945.